Expansion shield



Dec. 29 1925 C. C. TOMKINSON EXPANSION SHIELD Original Filed August 2 Illlilllll A'ITOR Patented Dec. -29, 1925i.

UNITED STATES PATENT oFFicE.

CHARLES C. TOMKINSON, OF '.PLAINFIELD, NEW JERSEY, ASSIG-NOR TO J. EDWARD OGDEN, OF MOUNTAINVILLE, NEW YORK.

EXPANSION SHIELD.

Original application filed. August 25, 1921, Serial No. 495,315. Divided and this application led October 1, 1924. Serial No. 740,901.

To all `whom z't'mwy concern:

Be it known that I, CHARLES C. TOMKIN- soN, a citizen of the United States, and a resident of Plainfield, county of Union, and State of New Jersey, United States of America, have invented certain new and useful Improvements in Expansion Shields, of which the following is a specification.

This invention relates to expansion shieldsfor bolt anchors such as are used in walls of brick, stone or cementitious material.

Expansion shields used in bolt anchors in which the shield is expanded by a nut carried by a bolt that bears directly against the bottom of the shield are termed bottom bearing shields. Tests of shields of this type have established the fact that the success of the shield is largely dependent upon `the strength of the bottom to resist the pressure of the bolt. When shields of this type are formed from sheet metal the thinness and ductility of the metal makes it desirable to have this bottom end solid and preferable to reinforce the bottom in some manner to w'thstand this thrust of the bolt.

The o ject 4of this invention is to provide an expansion shield made from a single piece of blank of sheet metal which forms an inner end or bottom. Another object is to so construct the shield that its inner or bottom end will be closed. vAnother object of the invention. is to provide a closed bottom shield formed of a single piece of material and requiring no securing means to secure a plurality of sections together. Another object of the inventionis to provide a. shield that is simple in construction and comprises a single piece stamping. A further object is to provide a reinforcement for the bottom of the shield, which reinforcement may be provided by folds of the imetal.

Fig.1 of the drawings is a plan view of a blank which is to be folded to form the improved expansion shield.

Fig. 2 is an end view of the folded shield made from the blank shown in Fig. 1.

Figs. 3 and 4 are longitudinal sectional views of the inner or bottom portion of the shield,'the views being taken at right angles to each other.

Fig. 5 is an elevation of the shield with a bolt and nut therein. l

Fig. 6 is a plan view of a sheet metal blank for a modified form of shield.

Fig. 7 is an nd View of a shield made from the blank shown ln Fig. 6.

Figs. 8 and 9 are longitudinal sectional views of the inner or Vbottom portion of the' shield made from the blank of Fig. 6, the views being taken at right angles to each other.A

The blank 10 shown in Fig. 1 is a rectangular piece of sheet metal with notches 11 cut in its longer sides. The central part of the blank, between the notches is bent and folded on the dotted lines indicated generally by the reference numeral 12 in- Fig. 1 to form the closed bottom 13 with two double-thickness, substantially triangular reinforcing ears 14 over its outer surface.

The end portions of the blank are bent into semi-cylindrical form with opposite edges abutting. This causes the notchesll to form diametrically opposed triangular openings 15 through the walls of the shield.

2O is a tapered nut having wedge projections 21 which extend into the openings 15. 22 is a bolt passing through the nut with its inner end abutting against the bottom of the shield.

If desired, the walls of the shield may be indented to form longitudinal ribs 16, the ends of which adjacent the nut may be tapered to fit the nut.

A circumferential groove 17 may also be provided near the outer end of the shield to receive a split ring 18 to assist in holding the parts forming the outer end of the shield together. v

When the bolt 22 is turned, the nut moves longitudinally and expands the shield to form a secure anchorage. In doing this, a thrust of the inner end of the bolt against the bottom of the shield is set up and therefore it is important to have. the bottom of the shield strong enough to` resist this thrust. This is accomplished by making the bottom of the shield of a solid piece of metal which is not distorted or stretched during the formation of the shield, and in the form of shield just described this bottom is strongly reinforced by the ears 14. The solid unperforated bottom also prevents dirt from the hole in which the shield is used fromentering the shield and clogging the threads of the nut and bolt.

A simpler form of shield may be made of the blank 30 of Fig. 6, of which the central portion 31 is substantially circular with integral rectangular ends 32 extending therefrom. lIhe longitudinal edges of these ends nearest the center are beveled as at 33 to form the wedge shaped openings '34 when the blank is bent and folded into a cylindrical shield. These openings receive the projecting wedgesl of such a nut as that shown at 20, in Fig. 5.

The bottom of this shield is solid and is formed of a part of the blank which is not distorted or stretched. If further reinforcement for the thrust of the bolt is desired, a washer 35 may be inserted in the shield under the expanding nut.

The embodiments of my invention herein described are taken from a copending application Serial No. 495,315, filed by me August 25, 1921, of which application this is a division. Other forms may be de-` vised Within the spirit and scope of this invention which is defined in the following claims.

What I claim is:

1. An expansion shield having diametrically opposed portions bent at right angles to the central portion to form laterally expansible sides of the shield and other portions between said opposed portions bent over the central portion.

2. An expansion shield having diametrically opposed portions bent at right angles to the central portion to form sides of the shield and other portions between said' opposed portions bent over the central portion and back to the side forming portions.

3. An expansion shield formed of a single piece of sheet metal having its inner end folded double into S shape'to form a reinforced bottom.

4. An expansion shield formed of a single piece of sheet metal with the central portion thereof forming a solid closed end, and doubled reinforcing means for said end.

5. A one piece expansion shield having its inner end closed and folded back on itself.

6. A one piece expansion shield having its inner end closed and having diametrically opposed doubled overlapping portions over its closed end.

7. A one piece sheet metal expansion shield having a central portion forming a closed bottom, and end portions bent from said central portion to fit a cylindrical wall opening, and an expanding member embraced by and contacting with the walls of said shield and movable longitudinally in the shield in contact therewith to expand the shield into permanent gripping engagement in the wall opening.

`8. A one piece sheet metal expansion shield having a central portion forming a closed bottom, and end portions bent from said central portion to form a lcylindrical shell, the edges of said end portion' being merges? beveled to form wedge-shaped openings in the cylindrical shell, and an expanding member within the shell having wings pro jecting into said openings.

9. A one piece sheet metal expansion 7 shield having a central portion forming a closed bottom, and end portions bent from said central portion to form a cylindrical shell, the edges of said end portion being notched to form Wedge-shaped openings in the cylindrical shell, and an expanding member within the shell having wings pro' jecting into said openings. i

10. A one piece sheet metal expansion shield formed of material of uniform thickness and having a central portion forming a closed bottom, and end portions having laterally expansible parallel sides bent from said central portion to form a closed cylindrical shell.

11. A one piece sheet metal expansion shield formed of material of uniform thickness and having a central portion forming a closed bottom, and end portions having parallel sides bent from said central portion to form a closed cylindrical shell, the edges of said end portions being beveled to form Wedge-shaped openings in the cylindrical shell, and an expanding member within the shell having wings projecting into said openings.

12. A one piece sheet metal expansion shield formed of material of uniform thickness and having a central portion forming a closed bottom, and end portions bent from said central'portion to form a cylindrical shell of single thickness `open at its outer end, and an expanding member movable in the shield from one end to the other to laterally expand the shield.

13. In combination, a one piece sheet metal expansion shield bent from a blank of uniform thickness and having a central portion which forms the inner end of the shield, and end portions which form shield side walls of single thickness, said end portions being bent from lthe central portion into parallelism with each other and transversely curved to fit a cylindrical hole and to leave the outer end of the shield open, and

an expanding member adapted to travel longitudinally in the shield and expand the side Walls thereof.

14. In combination, a one piece Sheet metal expansion shield formed from a blank of uniform thickness having substantially parallel edges, a bent portion forming fthe inner end of the shield and end portions' extending from the bent-portion to form longitudinal side Walls of single thickness, each wall being transversely curved to fit a. cylindrical hole and an expanding member adapted to travel longitudinall in and expand the shield walls and retain the shield Walls in expanded relation.

llO

15. In combination, a one piece sheet metal expansion shield formed from a blank of uniform thickness having substantially parallel edges, a bent portion forming the inner endof the shield and end portions extending from the bent portion in parallel relation and formin walls of single thick ness, each end portion being -transversely curved to fitV a cylindrical hole and an .ex-

panding member adapted to travel longitudinally in the shield and expand the shield into permanent gripping engagement with the wall of the opening 111 which the shield is positioned. 4

16. An expansion shield havin walls ofl uniform sin le thickness forme from a sin le piece lank bent to form longitudina y extending, transversely curved, laterally expansible walls, integrally bonded together at the inner end of the shield and an expander for said shield ada ted to travel longitudinally within the shield and expand the shield walls into gripping engagement with a wallv opening. i

In witness lwhereof, I have hereunto set my hand this 24th day of', September, '1924.

CHARLES C. TOMKIN SON. 

